Automatic draft regulator



Feb. 6, 1934. GARMAN 1,946,157

AUTOMATI C DRAFT REGULATOR Filed Jan. 28, 1932 grwwwm Mow m 0.

Patented Feb. 6, 1934 iJNi'rEo STATES PATENT @FFlCfiE 1 Claim.

This invention relates to draft regulators for furnaces, and aims to provide novel means whereby the draft on ash pit door and check draft will be automatically controlled by the heat of the i furnace, to the end that an even temperature in the rooms heated by the furnace may be maintained at all times.

An important object of the invention is the provision of a device of this character which will 1 comprise but few parts, and one which may be installed at a minimum cost, without the necessity-of making extensive alterations in the furnace construction.

A still further object of the invention is to provide a regulating means which will respond to the slightest variation in temperature beyond the normal degree of temperature for which the device is set, thereby providing a mechanism which will not only insure an even degree of temperature throughout the rooms heated, but one which will greatly decrease the cost of operation of the furnace and prolong the life of the furnace.

With the foregoing and other objects in view, which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed, may be made within the scope of what is claimed, without departing from the spirit of the invention.

Referring to the drawing:

Figure 1 is an elevational view illustrating a furnace equipped with a regulating device constructed in accordance with the invention.

Figure 2 is a sectional View taken on line 22 of Figure 1.

Referring to the drawing in detail, the reference character 5 designates the furnace with which the device is used, the furnace being of the usual and well known construction and including the dome 6, which is subjected to the direct heat from the fire of the furnace.

The control device includes a rod 7 which extends through an opening in the top of the furnace and engages the dome 6, in a manner as shown by Figure 1 of the drawing.

At the upper end of the rod '7, is a head 8, 'which is pivotally connected to the control arm 9, at 10, the control arm being provided with an extension 11 that has pivotal connection with the lever 12, which lever has pivotal connection with the bracket 13 that depends from the ceiling of the room in which the furnace is positioned.

The upper end of the control arm 9 is provided with hooks 14 and 15 respectively, the hook 14 providing means whereby one end of the cable 16 may be connected to the arm 9, the opposite end of the cable-being connected to the hinged check draft 17 which controls the draft through the chimney 18.

This cable 16 operates over the pulley 19 to the end that movement of the cable will be exceptionally free and sensitive.

Connected with the hook 14., is a coiled spring 20, which has one end thereof connected with the block 21, that is secured to the ceiling as shown by the drawing.

This spring 20 is of a construction to equalize the pull, and maintain the check draft normally closed. Connected with the hook 15, is a cable 22 which operates over the pulley 23, the opposite end of the cable being connected to the front draft on ash pit door 24.

It will of course be understood that when the front draft on ash pit door 24 is open, air will be admitted to the fire box in the usual manner to create a draft within the furnace.

From the foregoing it will be obvious that due to the construction shown and described, movement of the cable 16 in a direction to close the check draft 17, will act to move the cable 22 to open the draft in door 24.

When the cables 16 and 22 move in the opposite direction, the draft in door 24 will close, and the check draft 17 will open, cutting off the draft to the furnace.

Connected with the free end of the lever 12, is a cable 25 that moves over the pulleys 26 and 27, from where the cable pases upwardly connecting with the control dial in the room above, where the temperature can be adjusted and maintained without interfering with the coordination between draft 24 and check 17. Raising outer end of lever 12 automatically lowers the pivoted connection between lever 12 and lever 9, which automatically tilts lever 9 forward which closes front draft and opens check draft. Lowering outer end of lever 12 raises pivoted connection between lever 12 and lever 9, and coil spring pulls front draft open and closes check draft.

In the operation of the device: Assuming that the check draft and front draft are in positions as shown by Figure 1 of the drawing as the furnace cools, the dome 6 and '7 will contract allowing the spring 20 to pull the control arm laterally. With this lateral movement of the control arm, the check draft 17 is moved to its closed position, and the draft in door 24 is moved to its open position. A draft is nowcreated through the furnace and the dome and rod will expand under the action of the heat of the furnace.

As the dome and rod expand, the control arm' *9 is moved in the opposite direction, which results invention what is 7 device comprising a depending bracket above the furnace, a horizontal lever pivotally connected to the bracket near one end of the lever, providing a long end and a short end, a vertical control arm, a transversely disposed extension formed integral with the control arm at the lower end thereof, a vertical rod extending through the furnace top and engaging the dome of the furnace, one end of the transverse extension being pivotally connected to the upper end of the rod, the opposite end of the extension being pivotally connected with the short end of the lever, a cable connected to the control arm and having connection with the chimney check draft, a cable connected to the opposite side of the control arm and having connection with the ash pit door, whereby movement of the control arm will act to move the check draft and ash pit door, a cable connected to the lever, and a thermostat forcontrolling movement of the lever.

FRANK M. GARMAN. 

